JPH06101278B2 - Breaker - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grounded tank type circuit breaker with a resistor.

[0002]

2. Description of the Related Art FIG. 4 shows, for example, Mitsubishi Electric Technical Report Vol.
45 years) No. 9, page 1160, ultra-high voltage circuit breaker such as 500KV, using a closing resistor to suppress the surge that occurs during closing. In the figure, reference numeral 1 is a ground tank, which is filled with SF ₆ gas which is 2 insulating and extinguishing medium.
Reference numeral 2 is a main contactor, which is provided with a pair of main movable contactor and main fixed contactor in SF ₆ inside the insulating cylinder. Reference numeral 3 is a resistance contact, which is a pair of resistance movable contact and resistance fixed contact in SF ₆ in the insulating cylinder.

[0003] is provided. Usually, the main contactor 2 and the resistance contactor 3 are collectively referred to as an extinction chamber. Reference numeral 4 denotes a support body that supports these contacts, and this support body is supported by an insulator 5 provided so as to project from the ground tank 1. 6 is a resistor. In this example, one inverted L-shaped member is formed, one end of which is fixed to the tip of the resistance contactor 3, and the other end of which is connected to the main contactor 2 by a conductor 7. The axes of the main contactor 2, the resistive contactor 3, and the resistor 6 are displaced from each other in the vertical and forward / backward directions of the drawing sheet, and the central resistor (which looks like a T-shape) also collides with each other. There is no such thing.

Reference numeral 8 indicates a portion such as the resistor 6 which is a ground tank 1.
On the other hand, it is a cylindrical shield for mitigating the electric field, which is provided so as to obtain good insulation characteristics according to SF ₆ . Reference numeral 9 denotes a connecting conductor, which is adjacent to the main contactor 2 and the insulating spacer 10
It is connected to the conductor (11) fixed to. Reference numeral 12 is a capacitor for improving the potential distribution. Further, the circuit breaker has a structure in which, by the operation of the operating mechanism, the resistance contact 3 is closed 10 ms before the main contact 2 is closed and the resistor 6 is energized for 10 ms before the main contact 2 is closed. Then, at the time of breaking, the resistance contact 3 is opened early, and thereafter the main contact 2 is cut off, so that no current flows through the resistor 6.

With such a structure, it is possible to suppress a surge at the time of turning on the unloaded power transmission line, and it is possible to reduce the withstand voltage of the power transmission equipment. In the 500KV circuit breaker in Japan, a value of about 1,000Ω is most suitable for the resistor 6 used at this time, and even in a circuit breaker in which four extinguishing chambers are connected in series, the resistance at one location is 250Ω (1,000 Ω 1/4) is used. As shown in FIG. 4, the resistor 6 has an inverted L-shape having a total length of about 1 m and is formed in a columnar shape with a diameter of 10 cm bent in the central portion and has a weight of about 30 kg. Therefore, even if the resistor 6 is fixedly attached to the tip of the resistance contactor 3 and supported, it can withstand sufficiently, the volume occupied is small, and the problem of insulation was solved relatively easily.

[0006]

[Problems to be Solved by the Invention] However, even higher
It is considered that a breaker for 1,000 KV will also need a breaking resistance to suppress surges during breaking. At this time, about 500 Ω is required for the breaking resistance, but 1,000 for the closing resistance.
In case of KV, it may be 500Ω. Therefore, it is convenient to share the resistive contact 3 to simplify the structure and share the making and breaking resistors. Normally, the resistance is inserted for 10 ms when the power is turned on, and 30 ms when the power is cut off. Therefore, in the case of common use, when a series of operations of turning on and off is performed, the time during which the current flows is 1,000 times that when only turning on. The voltage doubles from 500KV to 1,000KV, and the resistance is halved from 1,000Ω to 500Ω. Therefore, since there is a relationship of the calorific value = (current flowing time) × (voltage) ² / (resistance),
Turned - When performing blocking continue, the ratio of the heating value of 1,000KV to 500KV, 32 (= 4 × 2 2/1/2) at twice. on the other hand,
The ultra-high voltage circuit breaker changes the number of the extinguishing chamber units to be connected in series according to the voltage, and the number of units is doubled at 1,000KV, so the heating value of the resistance per unit is 16 times. . The resistance is heat generated by a short-time current of 10 ms or 30 ms, and there is almost no heat dissipation during this period, while the resistor has an allowable temperature. Therefore, a resistor 6 having 16 times the heat capacity, that is, 16 times the weight and volume is required. The surge suppression resistor 6 having such a large weight is mounted so as to withstand vibration during an earthquake or during transportation, and the resistor 6 occupying a very large volume and a large capacity for obtaining a large current carrying capacity at all times. In order to provide the connecting conductor 9 of the shape in the ground tank 1 which is as small as possible while providing excellent withstand voltage characteristics,
The layout is an important issue.

The present invention has been made in view of the above, and provides a circuit breaker having excellent mechanical, electrical and thermal characteristics in such a tank circuit breaker having a large resistor. It is a thing.

[0008]

In the circuit breaker according to the present invention, a part of an extinguishing chamber consisting of a main contactor and a resistance contactor is supported by a first insulator which projects and is fixed to a ground tank. Also, a large volume resistance (surge suppressor) is supported by a second insulator that sticks out and is fixed to the ground tank, and the connection conductor connected in series with the main contact surrounds the resistor and also serves as a shield for electric field relaxation. It is to be provided.

[0009]

The circuit breaker according to the present invention has a mechanical strength sufficient to withstand earthquakes, transportation, etc., since it supports a heavy resistor (surge suppressor) with a dedicated insulator. Further, since the connection conductor also serving as the electric field relaxation shield is provided around the large resistance, the insulation characteristics between the resistor to which a high voltage is applied and between the ground conductor and the ground tank are excellent.
Further, since the connection conductor is installed around the resistor, it is possible to have a sufficiently large cross section, and it is possible to realize a circuit breaker that generates little heat even when a large current constantly flows and is excellent in heat.

[0010]

EXAMPLES Example 1. FIG. 1 shows a half of the circuit breaker embodying the present invention in a cross section parallel to the tank axis. The right half from point A is similar to this figure. In the figure, reference numeral 1 is a ground tank, which is filled with SF ₆ gas as an insulating and extinguishing medium. Reference numeral 2 is a main contact, which is composed of a main movable contact 2a and a main fixed contact 2b. Reference numeral 3 is a resistance contact, which is composed of a resistance movable contact 3a and a resistance fixed contact 3b. 13 is a support body that supports the movable contacts 2a and 3a, 14 is a support metal fitting that supports the main fixed contact 2b, 15
Is a metal support that supports the fixed resistance contact 3b. Support bracket
14 and 15 are connected to the support 13 by insulators 16 and 17, respectively. The support 13 is supported from the ground tank 1 by an insulating cylinder 18. The main movable contactor 2a is connected to the operation mechanism 22 via the link mechanism 19, the resistance movable contactor 3a via the link mechanism 20, and further via the insulating operation rod 21, and is driven by being connected to the operation mechanism 22. Reference numeral 23 is a resistor, which is assembled in a rod shape and is collectively arranged in substantially the center of the ground tank 1.

Reference numerals 24 and 25 denote support fittings having both ends of the resistor 23 fixed. The surge suppressor 26 is composed of 23, 24 and 25. Reference numeral 27 denotes a cylindrical insulator that supports the suppressor 26, and projects from the ground tank 1 and is fixed thereto. A connecting conductor 28 connects the resistor 23 and the fixed resistance contact 3a, and has flexibility. Reference numeral 29 is an insulating spacer that is connected to an adjacent device and serves as a gas barrier. Reference numeral 30 is a connecting conductor for connecting the supporting metal fitting 7 of the main fixed contactor 2b to the conductor 3 of the insulating spacer 29 or the supporting metal fitting 7 of another main fixed contactor, such as the resistor 23 which has a high voltage with respect to the ground tank 1. Also serves as a shield for relieving the electric field in the area. This connecting conductor 30 is a support fitting
It is supported by 24 and is connected by flexible conductors 32 and 33 to the support fitting 14 and the conductor 31 which will be the terminal portion. 34 is a shield for relaxing the electric field of the insulating spacer 29, and 35 is a capacitor for improving the potential distribution.

With the above-mentioned structure, even if the surge suppressor 26 has a large weight volume, it is supported by the dedicated support cylinder 27 having sufficient strength. Can withstand enough. In addition, since the connection conductor 30 that also serves as a shield for electric field relaxation is placed around the resistor 23 and its supporting metal fittings 24, 25 to which a high voltage is applied between it and the ground tank when energized, there is no electric field concentration and excellent insulation. The characteristics are obtained. Further, since the connecting conductor 30 covers the enclosing of the large resistor 23 by the shield, a cross-sectional area for energizing sufficiently large can be obtained even if it is thin, and even if a large current constantly flows, there is little heat generation, and it is thermally Can realize an excellent circuit breaker.

Example 2. 2 and 3 show another embodiment, and FIG. 2 shows a surge suppressor.
It is a sectional view of the vicinity of 26, and FIG. 3 shows a section taken along the line III-III in FIG. In the figure, 36, 37 and 38 are insulating rods having a resistor 23 having a hole in the center thereof, and a spring 39 is tightened with scissors metal fittings 40, 41 and 42 so that the resistor 23 comes into contact with a constant force. It is configured to do. 43 is an insulator, which electrically insulates.

In this example, since the resistor 23 is arranged by folding back, the length of the entire assembled state can be shortened and the breaker can be made compact. Further, since the connection conductor 30 also serving as a shield is arranged at the outermost part of the high voltage portion also as the electric field relaxation electrode, excellent ground insulation performance can be obtained. Furthermore, since the current-carrying cross-sectional area is large and the surface area that contributes to heat exchange is large, it is suitable for carrying a large current. In this case, the heat dissipation effect can be improved by dividing the shield 23 and providing a space above and below.

[0015]

As described above, according to the present invention, the part of the extinguishing chamber composed of the main contactor and the resistance contactor and the surge suppressor, which are provided adjacent to each other in the grounding tank, protrude from the grounding tank. Fixedly supported by separate insulators that are fixed together,
Surge suppressor for 1000KV circuit breaker that has both closing resistance and closing resistance because it has a structure in which a connecting conductor that also functions as a shield is formed outside the rod-shaped resistors that make up the surge suppressor. In the case of a surge suppressor with a weight of one digit or more as compared with the conventional input resistance for 500 KV only, it can have sufficient mechanical strength to withstand vibration during earthquakes and transportation. There are few places where the electric field is concentrated, and the withstand voltage performance is good.
It is possible to obtain a breaker suitable for energizing a large current.

[Brief description of drawings]

FIG. 1 is a sectional view of a circuit breaker showing an embodiment of the present invention.

FIG. 2 is a sectional view showing a main part of another embodiment of the present invention.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a cross-sectional view of a conventional breaker.

[Explanation of symbols]

 1 Ground Tank 2 Main Contact 3 Resistive Contact 18 First Insulator 24 Support Metal 25 Support Metal 26 Surge Suppressor 27 Second Insulator 30 Connection Conductor

Claims (1)

[Claims] 1. A first series body is constructed by connecting a main contact and a connecting conductor in series in a grounding tank filled with an insulating gas, and a surge suppressor and a resistance contact are connected in series. In a circuit breaker in which the second series body is connected in parallel with the first series body, the main contactor and the resistance contactor are supported by a common support, and the support is projected into the ground tank. The surge suppressor is composed of a plurality of rod-shaped resistors juxtaposed to each other, which are fixedly supported by the first insulator fixed to the grounding tank, and supporting metal fittings to which both ends of the resistors are fixed. , The surge suppressor is fixed to and supported by a second insulator that protrudes into the ground tank and is fixed to the ground tank, and the connection conductor surrounds the outside of the surge suppressor and also serves as a shield. A circuit breaker characterized by being configured as described above.